This proposal seeks to continue and expand the Training Program in Breast Cancer Research (TPBCR) at Vanderbilt University (VU). The TPBCR currently supports 5 predoctoral students/year to receive high-quality training in cancer research in general with a focus on breast cancer. The overall increase in specialized research targeted to breast cancer, the increase in breast cancer-funded and focused investigators at VU, the increasing institutional commitment to breast cancer research, and the increasing quality and interest of graduate students and postdoctoral Ph.D. and M.D. fellows on this endeavor provide a justification for continuation and expansion of this Program. We are requesting an increase to a total of 6 predoctoral and 2 postdoctoral positions/year in order to accelerate and enhance the quality of research leading to further understanding the pathogenesis of breast cancer and, in turn, the development of rational interventions to alter its natural history. The environment at VU provides all the elements to assure the sustained high quality of the TPBCR. This environment includes the Interdisciplinary Graduate Program in Biomedical Research, the Medical Scientist Training Program, the Breast Cancer Specialized Program of Research Excellence at the NCI-designated Vanderbilt-lngram Comprehensive Cancer Center, the Office of Biomedical Research Education and Training (BRET), the VU-Meharry Medical College (MMC) Alliance, the Fellowship in the Division of Hematology-Oncology, as well as vibrant and innovative institutional programs for outcomes analysis and post-training career enhancement. Due to the success of the TPBCR in the last 5 years, specific requirements for training in breast cancer research have been added in this application. The TPBCR preceptors have increased from 14 to 17 and now include 4 faculty members from MMC. There is additional emphasis on recruitment of minorities, the exposure of graduate students and Ph.D. postdoctoral fellows to translational and clinical aspects of breast cancer, and the inclusion of clinically-trained oncologists pursuing a career as physician-scientists focused in breast cancer research. The TPBCR is an essential component of the growing institutional research environment focused in breast cancer and represents a cornerstone upon which VU and MMC investigators train and will continue to train young scientists for a productive career in breast cancer research.